Vehicles such as automobiles typically have several lamps including head lamps and fog lamps. These lamps generally include a housing supporting a reflector (which is typically mounted within the housing on a mounting bracket) and a lens with a bulb mounted therebetween, the entire lamp assembly being attached to the vehicle. Examples of such a configuration are shown in U.S. Pat. Nos. 5,707,133 and 6,974,231 to Burton. Once the lamp assembly has been manufactured and installed into a vehicle, the lamp must be adjusted to the proper aim. Typically the adjustment is in both the vertical and horizontal directions but, depending on the type of lamp and applicable regulations, adjustment in only one direction may be required. As a result of accidents, maintenance, and normal vibrations and wear, the aim of the lamp may need to be occasionally adjusted during the lifetime of the vehicle as well.
One method of adjusting the aim of the lamp involves using an adjuster. The adjuster may be formed as part of the mounting bracket, part of the housing, or may be a separate part between the housing and the mounting bracket (or the reflector directly if no separate mounting bracket is used). One known type of adjuster includes a housing and an output shaft extending therefrom. The output shaft is engaged to the reflector directly or to a mounting bracket on which the reflector is positioned. Actuation or operation of the adjuster causes the output shaft to move. Such movement causes the mounting bracket and/or reflector to pivot or otherwise move with respect to the housing, thereby adjusting the aim of the lamp. One example of this type of adjuster is disclosed in U.S. Pat. No. 6,773,153 to Burton, the disclosure of which is incorporated herein by reference for all purposes. The housing of the adjuster in this Burton design has an opening and a gear positioned inside the housing. The gear is functionally engaged to a ball stud output shaft. An input shaft is positioned in the opening and interacts with the gear. Actuation of the input shaft results in rotation of the gear and engaged output shaft. The gear translates actuation of the input shaft into axial movement of the output shaft and its ball stud end. Numerous variations exist on this general concept.
Providing end of travel clutching regardless of resistance present is desirable to prevent adjuster disengagement or damage to the headlamp components, the reflector and mounting bracket in particular. One method for accomplishing end of travel clutching is disclosed in U.S. Pat. No. 6,773,153 to Burton. It is also desirable to have clutching along the length of travel if an undue axial force is present. Standardization of adjusters is desired in the industry which means using one length of travel for many different lamp designs. This creates the possibility of having the adjuster length of travel exceed that of the reflectors' range of motion in a particular lamp design. When the length of travel of the adjuster exceeds the reflectors' range of motion it may collide with other lamp components such as the lamp housing, bezel, or lens. If adjustment continues after a collision between lamp components occurs, a resistance force builds. Damage or fracture of lamp components may result with undue resistance. Having an adjuster that clutches prior to undue resistance could prevent this from occurring. Examples of adjusters with length of travel clutching are described in U.S. Pat. No. 7,762,686 to Fladhammer and U.S. Pat. No. 6,017,136 to Burton.
Thus, it is desirable to have an adjuster that combines effective length of travel clutching when an undue resistance is present with end of travel clutching regardless of resistance present. It is also desirable to minimize clutching force variation along the length of travel because damage can occur to lamp, ball socket, or adjuster components if the clutching force varies too high. And if the clutching force varies too low, this could prevent achieving the desired aim (positioning).
Accordingly, a need exists for an improved lamp adjuster that solves these and other deficiencies in the prior art. Of course, the complete travel length clutching adjuster may be used in a multitude of situations where similar performance capabilities are required. It will be understood by those skilled in the art that one or more aspects of the complete travel length clutching adjuster can meet certain objectives, while one or more other aspects can lead to certain other objectives. Other objects, features, benefits and advantages of the complete travel length clutching adjuster will be apparent in this summary and descriptions of the disclosed embodiment, and will be readily apparent to those skilled in the art. Such objects, features, benefits and advantages will be apparent from the above as taken in conjunction with the accompanying figures and all reasonable inferences to be drawn therefrom.